Science (English Medium) Class 12 - CBSE Question Bank Solutions for Chemistry

The decomposition of hydrocarbon follows the equation

k = `(4.5 xx 10^11 s^-1) e^(-28000 K//T)`

Calculate E_a.

The decomposition of A into product has value of k as 4.5 × 10³ s⁻¹ at 10°C and energy of activation 60 kJ mol⁻¹. At what temperature would k be 1.5 × 10⁴ s⁻¹?

The rate of a reaction quadruples when the temperature changes from 293 K to 313 K. Calculate the energy of activation of the reaction assuming that it does not change with temperature.

The rate constant for the first order decomposition of H₂O₂ is given by the following equation:

log k = 14.34 − 1.25 × 10⁴ K/T

Calculate E_a for this reaction and at what temperature will its half-period be 256 minutes?

What role does adsorption play in heterogeneous catalysis?

Give four examples of heterogeneous catalysis.

Out of C and CO, which is a better reducing agent at 673 K?

Giving examples, differentiate between ‘roasting’ and ‘calcination’.

Why copper matte is put in silica lined converter?

Out of C and CO, which is a better reducing agent for ZnO?

Give evidence that [Co(NH₃)₅Cl]SO₄ and [Co(NH₃)₅SO₄]Cl are ionisation isomers.

Write the free radical mechanism for the polymerisation of ethene.

What is meant by the term ‘broad spectrum antibiotics’? Explain.

Name a substance which can be used as an antiseptic as well as disinfectant.

What are the main constituents of dettol?

What is tincture of iodine? What is its use?

Arrange the following:

In decreasing order of the pK_b values:

C₂H₅NH₂, C₆H₅NHCH₃, (C₂H₅)₂NH and C₆H₅NH₂

Arrange the following:

In increasing order of basic strength:

C₆H₅NH₂, C₆H₅N(CH₃)₂, (C₂H₅)₂NH and CH₃NH₂

Arrange the following:

In increasing order of basic strength:

Aniline, p-nitroaniline and p-toluidine